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[fitbrit]

I have my custom display modes to always play at 3840x2160 on the HTPC. However, for readability purposes we have the Windows display scaling set to 175% in the living room. When I look at MadVR stats, or the Zoom setting in the OSD, I see that MC is downscaling the image to 57%. This is obviously to compensate for the 175% Windows scaling. But is MC really downscaling and then letting Windows upscale, even when the native resolution of the video is 3840x2160p? Or is it just that this is what the software has to report, and the image I am seeing is untouched?

I don't seem to recall this always happening. I seem to recall that video would play (and report in MadVR) that it was playing at 3840x2160 regardless of the Windows scaling setting. But then again I seem to remember lots of things that didn't ever happen and forget those that did!
Happy to provide further information if needed.

[tij]

It was always like this ... MadVR will upscale by DPI setting (in your case by 175%) ... you can see this in MadVR OSD

Then something else (MC? ... Windows?) downscales befire output.

I dont think its just software reporting ... image is defenitely being scaled by MadVR - GPU utilization goes up by a lot.

This has been discussed before ... but most ppl say modern GPU is powerful enough to do this ... as i have walk around for this, i did not press on the issue ... at the time it was more important for me to get SSA/ASS subtitles implemented ... which it was

EDIT: not sure if this is jyst MC ... or other players using MadVR (MPCHC or VLC) are doing this too ... as i had no time to test

EDIT2: this might also be reason Theatre View is experiencing high GPU use for some users

On my system (nvidia 1070... with DPI bypassed for MC)  ... 2160p23 Theatre View is nornally using around 8% of gpu ... on 2160p60 use is around 9% ... in both cases ocassionally hitting around 24% use

EDIT3: tried turning off my DPI bypass for MC ... funny thing happens ... at 175% DPI , MadVR does not scale ... at 125% DPI, MadVR scales ... some funky logic here ... GPU dependant? ... driver dependant? ... MC dependant?

[fitbrit]

Thanks Tij

I think you have it backwards. According to MadVR and MC OSD, MadVR is downscaling the image and Windows is then upscaling it. Thanks for confirming that this is going on.

My second comment for you is a question - how did you bypass MC from the Windows DPI settings?

[tij]

Thanks Tij

I think you have it backwards. According to MadVR and MC OSD, MadVR is downscaling the image and Windows is then upscaling it. Thanks for confirming that this is going on.

My second comment for you is a question - how did you bypass MC from the Windows DPI settings?

sent you PM ... the developers don't like this mentioning as it can cause more trouble than it solve for average user

[tij]

here is what happen to my system if I don't bypass DPI

[fitbrit]

What scaling is Windows set at for you?
Very interesting indeed, as I have mine set to 175% and it downscales the image.
When I just tried 200%, MadVR was scaling down to 1080p.

[tij]

That image i posted is 125% ... so it looks like our system work opposite ... mine scales up - yours scale down ... some funky stuff

As i mention before at 175% - no scaling happens ...

I can do more testing, if JRiver wants to fix the problem ... but its not critical to me since i can bypass it

[fitbrit]

So our differing results, plus my confirmation that many of the systems I build with integrated AMD or Intel graphics do not scale has got me intrigued. Would love to get to the bottom of this!

[Hendrik]

This works just fine if you have just one screen, or your primary screen is the one intended for video playback. If you mix screens with different DPI settings, such behavior can occur, as MC only handles one global DPI, not per screen changes.

[tij]

I only have one screen attached to 1070 ... onbord igpu is disabled in bios

[tij]

This works just fine if you have just one screen, or your primary screen is the one intended for video playback. If you mix screens with different DPI settings, such behavior can occur, as MC only handles one global DPI, not per screen changes.

Imho ... when video is played in full screen, DPI should not be applied to it

Also DPI should not be applied to Theatre View too

Just my 2 cents

[Hendrik]

Imho ... when video is played in full screen, DPI should not be applied to it

Also DPI should not be applied to Theatre View too

Fullscreen or not is entirely irrelevant to that. Windows handles most of that, and you can't just turn it on or off. And if you have only a single screen and not messed with the DPI settings on the MC process, then it functions just fine here.

Oh, you are also not allowed to change resolution between different resolutions with different DPI, as for Windows that has the same effect as having multiple monitors. But actually changing resolution for video playback is IMHO the wrong thing to do in any circumstance. If you have one screen with one resolution (or all screens have the same resolution/dpi), or in other words, one value for DPI only, then it is handled entirely transparently.

[tij]

I stop changing resolution since i switched to top/bottom 3d ... so all my movies play at 2160p ... only thing get switched is fps.

But i can see ppl want to switch resolutions:
1. Ppl who still want to output 3D in frame pack and play 4k movies (3D framepack is only supported at 1080p)

2. Ppl who wants to use their expensive Envy or Lumagen to do scaling and want to output video in original resolution

Also ... this MadVR scaling per DPI - is transparent ... unless you turn OSD on - you would not know its happening (though it does consume GPU resources which could have been used for better scaling or post processing ... and quality of picture does seem to degrade fractionally with exra scaling up and scaling back down ... )

But this doesnt bother me ... so i will just drop it

[tij]

If you have one screen with one resolution (or all screens have the same resolution/dpi), or in other words, one value for DPI only, then it is handled entirely transparently.

That got me thinking ... as long time ago I had a second monitor attached to system for debugging that probably had a DPI setting different from my current TV.

Typical of Windows, it was likely that Windows stored DPI setting for that second monitor which screw up with my MadVR scaling.

As I cannot change DPI of that second monitor any longer to match my current TV (I dont even have it now), I tried this (this set DPI for all displays to same value ... i was hoping it will override value stored for that second monitor, which it did)

In Windows: [Display Setting]->[Scale and Layout]->[Advance Scaling Settings] ... I then entered my desired scaling into "Enter a custom scaling size..."

It required me to sign out for effect to take effect ... but after that no more unnecessary MadVR scaling

Hope this helps someone with similar problem

[fitbrit]

Thanks for chiming in, Hendrik. I'm sorry, I lost track of this thread for a while.

I too never change resolutions, only refresh rate. However, my video card is connected to two different inputs on my AVR, and the "two displays" are set to be mirrored. THis was done so I could play two channel audio through a different, non-HDMI output, and still have the picture I was expecting to see in MC.
Both displays should show up as being identical. The only thing that is changing is the refresh rate.